1. Field of the Invention
The present invention relates to heat dissipation devices, and more particularly to heat dissipation devices which can be safely attached to heat-generating devices and which have great heat removal capability.
2. Description of Related Art
Most computer central processing units (CPUs) are secured to a mother board in a zero inserted force (ZIF) socket. To ensure normal operation of a CPU, a heat dissipation device is attached to a top surface of the CPU to remove heat generated therefrom.
A common heat dissipation device for a CPU comprises a heat sink and a clip. The clip spans across the heat sink, and is engaged with a socket. A bottom surface of the heat sink is attached on a top surface of the CPU. A thermally conductive material is applied to the bottom surface of the heat sink. The material fills gaps between the heat sink and the CPU, to enhance thermal conductivity between the heat sink and the CPU. This gives the heat dissipation device greater heat removal capability.
However, the material applied to the bottom surface of the heat dissipation device is sticky, and is in direct contact with the top surface of the CPU. The material may bind the CPU and the heat sink together. When this happens, and if the heat dissipation device is accidentally moved or displaced, the heat dissipation device can easily pull the CPU out from the ZIF socket. This frequently occurs when the mother board is subjected to shock or vibration. The CPU is liable to be damaged when it is accidentally pulled out from the socket.
Accordingly, an object of the present invention is to provide a heat dissipation device which protects a CPU from being removing from a CPU socket when force is unintentionally exerted on a heat sink of the heat dissipation device that is in thermal contact with the CPU.
In order to achieve the object set out above, a heat dissipation device comprises a heat sink, a metal plate and a clip. The heat sink has a chassis with thermally conductive material applied thereunder. The metal plate is attached to the material in order to be in thermal contact with the chassis. The metal plate is then directly attached to a CPU. The clip is engaged with a socket that supports the CPU, to facilitate the metal plate intimately contacting the CPU. The metal plate prevents the CPU from moving from the socket should the heat dissipation device be accidentally moved or displaced. This reduces any risk of damage to the CPU. In addition, heat generated from the CPU is efficiently removed.